<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js WebGL 2 - buffergeometry - attributes - none</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<link type="text/css" rel="stylesheet" href="main.css">
	</head>
	<body>

		<div id="info"><a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> WebGL 2 - buffergeometry - attributes - none</div>

		<script id="vertexShader" type="x-shader/x-vertex">

			uniform mat4 modelViewMatrix;
			uniform mat4 projectionMatrix;

			uniform float seed;

			const uint ieeeMantissa = 0x007FFFFFu;
			const uint ieeeOne = 0x3F800000u;

			uint hash(uint x) {
				x += ( x << 10u );
				x ^= ( x >>  6u );
				x += ( x <<  3u );
				x ^= ( x >> 11u );
				x += ( x << 15u );
				return x;
			}

			uint hash(uvec2 v) { return hash( v.x ^ hash(v.y) ); }

			float hashNoise(vec2 xy) {
				uint m = hash(floatBitsToUint(xy));

				m &= ieeeMantissa;
				m |= ieeeOne;

				return uintBitsToFloat( m ) - 1.0;
			}

			float pseudoRandom(float lower, float delta, in vec2 xy) {
				return lower + delta*hashNoise(xy);
			}

			vec3 pseudoRandomVec3(float lower, float upper, int index) {
				float delta = upper - lower;
				float x = pseudoRandom(lower, delta, vec2(index, 0));
				float y = pseudoRandom(lower, delta, vec2(index, 1));
				float z = pseudoRandom(lower, delta, vec2(index, 2));
				return vec3(x, y, z);
			}

			out vec3 vColor;

			void main()	{

				const float scale = 1.0/64.0;
				vec3 position = pseudoRandomVec3(-1.0, +1.0, gl_VertexID/3) + scale * pseudoRandomVec3(-1.0, +1.0, gl_VertexID);
				vec3 color = pseudoRandomVec3(0.25, 1.0, gl_VertexID/3);
				gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0 );
				vColor = color;

			}
		</script>

		<script id="fragmentShader" type="x-shader/x-fragment">

			precision mediump float;

			in vec3 vColor;

			out vec4 fColor;

			void main()	{

				fColor = vec4(vColor, 1);

			}
		</script>

		<script type="importmap">
			{
				"imports": {
					"three": "../build/three.module.js",
					"three/addons/": "./jsm/"
				}
			}
		</script>

		<script type="module">

			import * as THREE from 'three';

			let camera, scene, renderer, mesh;

			init();

			function init() {

				camera = new THREE.PerspectiveCamera( 27, window.innerWidth / window.innerHeight, 1, 3500 );
				camera.position.z = 4;

				scene = new THREE.Scene();
				scene.background = new THREE.Color( 0x050505 );
				scene.fog = new THREE.Fog( 0x050505, 2000, 3500 );

				// geometry

				const triangleCount = 10000;
				const vertexCountPerTriangle = 3;
				const vertexCount = triangleCount * vertexCountPerTriangle;

				const geometry = new THREE.BufferGeometry();
				geometry.setDrawRange( 0, vertexCount );

				// material

				const material = new THREE.RawShaderMaterial( {
					uniforms: {
						seed: { value: 42 },
					},
					vertexShader: document.getElementById( 'vertexShader' ).textContent,
					fragmentShader: document.getElementById( 'fragmentShader' ).textContent,
					side: THREE.DoubleSide,
					glslVersion: THREE.GLSL3
				} );

				// mesh

				mesh = new THREE.Mesh( geometry, material );
				mesh.frustumCulled = false;
				scene.add( mesh );

				// renderer

				renderer = new THREE.WebGLRenderer( { antialias: true } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );
				renderer.setAnimationLoop( animate );
				document.body.appendChild( renderer.domElement );

			}

			function animate( time ) {

				mesh.rotation.x = time / 1000.0 * 0.25;
				mesh.rotation.y = time / 1000.0 * 0.50;

				renderer.render( scene, camera );

			}

		</script>

	</body>
</html>
